Re: dh_insert: bad deref in chain for ...

Hi Chris,

>    len = sizeof (struct chain) + strlen(dp->messageid) + 1 - sizeof (chp->messageid);
> 
> But if chp is NULL, this will end the while loop and the next
> statement should segfault because of 'sizeof(chp->messageid)',
> shouldn't it?

`sizeof' isn't a run-time function but a compile-time operator.  What
chp points to doesn't affect the size of chp->messageid.  This is useful
because it allows

    sizeof(((foo *)NULL)->bar)

without having to have a variable of type `foo' to hand, e.g. in a
preprocessor macro definition.

Cheers,


Ralph.